"Detect Gym Equipment" missing in Apple Watch > Settings > Workout on Child's Apple Watch

Hi all, I am posting because I was having an issue that I solved, but I couldn't find any documentation online for it. When I called Apple Support I spoke with a senior Apple Fitness advisor and they had no information on the subject on their end either. Hopefully this post will help other people.

In short, I bought my child an Apple Watch SE. He is under 13 and during setup I opted for the Under 13 non-calorie ring option. However, we have a treadmill that he wanted to use and it supports GymKit. However, when he swiped his watch, nothing happened. In digging around on the internet, the only thing I could figure out was that "Detect Gym Equipment" might be disabled (I forgot this existed), which can be found in Apple Watch > Settings > Workout. However, when I went to that location the option didn't exist. It should be before "Units of Measure." You will see in one of the screen grabs it's not there.

In the call with Apple they couldn't figure out why the option wouldn't be there and the rep figured it had to do with a safety setting. I elected to turn off "Under 13 years old," which is found under Fitness > Account > Under 13 Years Old on the paired iPhone (you can do it through the Watch app > Family Watches > Activity tab if you setup the watch through Family Member).

When you turn it off, you will receive a notification that the setting will not take effect until the next morning. I checked the watch, no GymKit (yet), but when I checked the next morning "Detect Gym Equipment" was now in Apple Watch > Settings > Workout. It would appear that the under 13 setting affects the GymKit functionality (my guess is because it doesn't track calories, rather move minutes and there is a blurb "Outdoor run, walk, hike, and cycle are tuned for this age group in Workout." and maybe that means GymKit changes too).

I hope it helps!